Grinding or crushing mill.



No. 388, 72); PATENTED APR; 7, 190's. ;T.J.P-RASER.

' GRINDING 0R GRUSHING MILL.

APPLICATION III-JED MAY 31. 1906.

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UNITED STATES PATENT OFFICE.

JAMES JOHNSTONE FRASER, OF'LEITH, SCOTLAND.

GRINDING OR CRUSHING MILL.

To all whom it may concern:

Be it known that I, JAMEs JoHNs'roNE FRASER, a subject of the King ofGreat Britain and Ireland, and a resident of Leith, in the county ofMid-Lothian, Scotland, (whose postal address is 49 Dalmeny street,Leith, Scotland,) have invented certain new and useful Improvements inor Relating to Grinding or Crushing Mills, (for which I have obtained aBritish patent, No. 17,200, dated August 25, 1905,) of which thefollowing is a description.

My said invention has for its object to improve and simplify theconstruction and action of grinding or crushing mills.

In carrying out my invention there is mounted on a shaft, carried insuitable bearings in the framing of the mill, a disk which is keyed toand rotates with the shaft. To one face of this disk there is appliedany well known kind of grinding composition, while to the other face ofthe disk there is secured by screwing or otherwise a number of studs orprojections which according to my invention are of a dovetailed-likeformation. Two non-rotating disks are as usual arranged, one on eachside of, and adapted to work against each face of the rotating disk. Thegrinding face of one of the non-rotating disks has applied to it anywell known grinding composition to work against the corresponding faceof the rotating disk while the grinding face of the other non-rotatingdisk has a number of dovetailed-like studs or projections fitted to-it,to work againstthe corresponding face of the rotating disk. Ifpreferred, the working face or faces of each disk may be provided with agrinding composition. Means are provided for adjusting the non-rotatingdisks, and also for feeding the material to be ground to the grindingsurfaces of the disks. If desired only one non-rotating disk may beused.

-In order that my said invention and the manner of performing the samemay be properly understood I hereunto append a sheet of explanatorydrawings showing a sectional elevation of a grinding or crushing mill asmade according to my invention.

As shown in the drawing, the shaft, A, carried in suitable bearings, B,in the framing, C, of the mill, has mounted on it a disk, D, said diskbeing keyed to and rotating with the shaft. To one face of the disk, D,there is applied any well known grinding composition, E, while to theother face of the disk a Specification of Letters Patent.

Application filed May 31, 1906.

Patented April 7, 1908.

Serial No. 319,635.

number of studs or projections, F, of a dovetailed-like formation, aresecured by screwing or otherwise. Two non-rotating disks, G, H, arearranged one op osite to each face of the rotating disk, D, an to theface of one of the non-rotating disks, G, there is applied a grindingcomposition, J, while to the face I of the other non-rotating disk, H,there are secured a number of studs or projections, K, of adovetailed-like formation. Any convenient number of rows of those studsor projections, F, and K, may be used, the studs in one row beingpreferably arranged at intermediate points to the studs in the next row.The rotating and non-rotating disks, D, G, and H, are inclosed within acasing, L, and two annular passages or spaces, M, are formed within thecasing to receive the ground material after it has passed between thegrinding faces of the disks.

The non-rotating disks, G, and H, have each an elongated tubular hub orextension,

N, and bearing against the outer end there is G, and H, can be adjustedrelative to the rotating disk, D. If desired only one non-rotating diskmay be used.

A screw feeding device, V, mounted on and rotating with the shaft, A, isarranged within the hub or tubular extension, N, of each nonrotatingdisk, G, and H.

The dovetailed-like studs or projections, F, and K, instead of beingused as grinding surfaces, may be utilized to secure to the face of thedisks any well known grinding composition.

In operation the action of the mill is as follows :-The material to beground is fed from any suitable hopper (not shown) and passes downthrough one or other of the openings, W, to the screw feeding device, V,which propels it towards the disks, D, G, and H. As the material is nowrotating at a comparatively high speed, it is by centrifugal forcedriven towards and between the grinding surfaces of the disks. After thematerial has passed between the disks it escapes into one or other ofthe annular passages, M, and is discharged through one of the openings,Y, in the bottom of the casing, L. When bones and such like material isto be ground, it is first passed between what might be termed thepreparatory grinding surfaces, consisting of the studs or projections,F, and K, and afterwards finally ground between the grinding surfaces, Eand J.

What I claim is A grinding mill comprising a rotary shaft uprights forsupporting the same, a rotary disk mounted on said shaft and having agrinding surface on one side and dove tailed projections on the otherside, a non-rotating disk on each side of the rotary disk, one of saidnon-rotating disks having a grinding surface adapted to enga e with thegrinding surface on the rotary disk and the other disk having dovetailed projections thereon adapted to engage with the projections on therotary disk, said non-rotating disks having hollow hubs, a casingsurrounding the peri heries of said disks, said casing having out etstherefrom and two annular passages therein, one passage receiving thematerial passing from the projections and the other passage the materialfrom the grinding surfaces, means for feeding the material through thehollow hubs of the non-rotating disks and means for moving saidnon-rotating disks towards and from the rotary disk.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

JAMES JOHNSTONE FRASER.

